The following line graph shows the ratio of the amount of imports by a Company…

Concept: To find the percentage increase in an absolute quantity such as imports between two years, the actual value of that quantity is needed in both years. A ratio between two quantities (imports to exports) only gives their relative proportion — it does not by itself reveal either quantity's absolute size, because the same ratio can correspond to many different pairs of absolute values.

Application: The graph plots only the ratio (Imports ÷ Exports) for each year — 0.35 for 1997 and 1.25 for 1998. Nowhere in the graph, its caption, or the passage is the absolute import or export figure given for any year. Since imports = ratio × exports, computing the actual percentage increase in imports needs the exports figures for 1997 and 1998 (or the imports figures directly) — neither is available, and nothing else in the question supplies them.

Cross-check: Manipulating the two ratio numbers in different ways confirms this — each only changes the RATIO, never the actual import amount:

• (1.25 − 0.35) ÷ 1.25 × 100 = 72% — still just a ratio change

• (1.25 − 0.35) ÷ (1.25 + 0.35) × 100 ≈ 56% — still just a ratio change

• 0.35 ÷ 1.25 × 100 = 28% — still just a ratio change

Since the exports figures needed to convert the ratio into an absolute import value are never given, the data is inadequate to determine the percentage increase in imports from 1997 to 1998.